HS2-6 Head Face Scalp Flashcards
What are the two primary divisions of the skull?
neurocranium
viscerocranium
Which bones form the viscerocranium?
maxilla
zygomatic
palatine
mandible
vomer
inferior nasal cocha
lacrimal
nasal
What structures comprise the major arterial supply to the head overall? (3)
internal carotid artery
external carotid artery
vertebral artery
What structures comprise the major arterial supply to the neurocranium? (3)
internal carotid artery
external carotid artery
vertebral artery
What structures provide arterial supply to the inside of the neurocranium? (3)
internal carotid artery = brain
vertebral artery = brain
middle meningeal artery (indirect branch of external carotid) = inside of skull
What structures provide arterial supply to the outside of the neurocranium? (2)
branches of the external carotid:
superficial temporal artery
occipital artery
What provides arterial supply to the viscerocranium?
external carotid artery
What provides arterial supply to the outside of the face?
facial artery, a branch of the external carotid
What provides arterial supply to the inside of the face?
maxillary artery, a branch of the external carotid
What provides arterial supply to the orbit?
ophthalmic artery, a branch of the internal carotid
What provides venous drainage for the inside of the neurocranium?
dural sinuses, which drain into internal jugular vein
What provides venous drainage for the outside of the face?
facial vein and retromandibular veins, which drain into external jugular vein
What structures form the boundaries of the “danger area of the face?”
facial vein
upper lip
bridge of nose
Why is the “danger area of the face” named so?
because veins of the head and neck don’t have valves, infection/metastases from this area can easily travel to the cranial cavity from facial vein → opthalmic vein → cavernous sinus
Superficial lympathic drainage of the face and scalp leads to
the superficial lymph nodes of the neck
Lymphatic vessels of the face and scalp drain into
deep cervical lymph nodes
How is lymph returned to the systemic venous system? (2)
on left side, via thoracic duct
on right side, via right lymphatic duct
List the nerves that provide sensory innervation for the head. (2)
branches of trigeminal nerve (CN V) supply most of face
branches from dorsal (e.g. greater occipital) or ventral (e.g. great auricular) primary rami supply rest of head
List the three major divisions of the trigeminal nerve.
ophthalmic division (CN V1)
maxillary division (CN V2)
mandibular division (CN V3)
What are the modalities of the trigeminal nerve for the head? (2)
general sensory to face
some motor to head
The ophthalmic division (CN V1) provides innervation to (1, +4):
sensory only:
orbital region (forehead, anterior scalp, upper eyelid, dorsum nose)
The maxillary division (CN V2) provides innervation to (1, +4):
sensory only:
midface area (lower eyelid, side of nose, upper lip, upper dentition)
The mandibular division (CN V3) provides innervation to (2, +3, +1):
sensory:
lower dentition
skin anterior to ear
inside of oral cavity
motor:
muscles of mastication
Broadly speaking, what is the function of the facial nerve?
motor innervation to face
How many terminal motor branches of the facial nerve are found on the face?
5
What are the four major muscles of facial expression?
occipitofrontalis (frontal belly)
orbicularis oculi
buccinator
orbicularis oris
Describe how the orbicularis oculi contributes to facial expression. (2)
orbital part tightly closes eye
palpebral part for blinking
Describe how the orbicularis oris contributes to facial expression. (2)
closes mouth
puckers lips
Describe how the buccinator contributes to facial expression. (2)
compresses cheeks against teeth and gums during chewing
expels air from distended cheeks
Describe how the occipitofrontalis contributes to facial expression. (3)
occipitalis moves scalp to smooth skin of forehead
frontalis raises eyebrows and wrinkles forehead
occipitofrontalis moves entire scalp forward and backward
What is the composition of the occipitofrontalis muscle?
occipital and frontal components, connected by epicranial aponeurosis
What is Bell’s palsy?
sudden, unilateral, idiopathic facial paralysis
What are the clinical symptoms of Bell’s palsy? (3)
drooping of mouth
cannot close lips
cannot close eye
What is the likely cause of Bell’s palsy?
viral origin causing inflammation of facial nerve
What are the layers of the scalp?
mnemonic: SCALP
S = skin
C = connective tissue (i.e. fascia + collagen)
A = aponeurosis (tendinous layer from occipitofrontalis)
L = loose connective tissue (areolar)
P = pericranium
What are the four primary veins that function in venous drainage of the head/neck area?
internal jugular
external jugular
subclavian
brachiocephalic
Describe the function and pathway of the internal jugular vein.
drains brain + cervical viscera into brachiocephalic vein
Describe the function and pathway of the external jugular vein.
drains face + scalp into subclavian vein
Describe the pathway of the subclavian vein.
[receives from external jugular] → subclavian vein → braciocephalic vein → superior vena cava
Write out the overall pathway for lymphatic drainage in the neck.
What are the roofing bones of the skull?
frontal
temporal (squamous portion)
parietal
How are the roofing bones of the skull formed?
intramembranous ossification
What are the basal bones of the skull?
ethmoid
sphenoid
temporal (petrous portion)
occipital
How are the basal bones of the skull formed?
formed through endochondrial ossification
What are the layers of the roofing bone?
periosteum
outer cortical
diploë
inner cortical
periosteum
What is the significance of the diploë layer of the roofing bones?
contains venous channels, which can potentially spread infection
List the anatomical events that culminate in an epidural hematoma. (4)
side trauma to head → pterion fracture → rupture of middle meningeal artery → epidural hematoma
List the pathway for lymphatic drainage of the face and scalp.
Draw a rough sketch of a lateral view of the head and show which nerves contribute to sensory innervation.
Explain the clinical significance of the loose connective tissue layer of the scalp. (3)
easily torn
bleeds a lot
allows superficial layers to slide
